O.K.

"O.K." is an Americanism that has swept the world. Consequently it is a great target for linguists. Where did the phrase come from?

The man responsible for unraveling the mystery behind “OK” was an American linguist named Allen Walker Read. An English professor at Columbia University, Read dispelled a host of erroneous theories on the origins of “OK,” ranging from the name of a popular Army biscuit (Orrin Kendall) to the name of a Haitian port famed for its rum (Aux Cayes) to the signature of a Choctaw chief named Old Keokuk.

During the late 1830s, it was a favorite practice among younger, educated circles to misspell words intentionally, then abbreviate them and use them as slang when talking to one another. (Reminiscent of the Cockney rhyming speech.)

The initials “O.K.” were first published in The Boston Morning Post in 1839. It was meant as an abbreviation for “oll korrect,” a popular slang misspelling of “all correct” at the time. OK steadily made its way into the everyday speech of Americans.
It was picked up by contemporary politicians. When the incumbent president Martin Van Buren was up for reelection, his Democratic supporters organized a band of thugs to influence voters. This group was formally called the “O.K. Club,” which referred both to Van Buren’s nickname “Old Kinderhook” (based on his hometown of Kinderhook, New York), and to the term recently made popular in the papers. At the same time, the opposing Whig Party made use of “OK” to denigrate Van Buren’s political mentor Andrew Jackson. According to the Whigs, Jackson invented the abbreviation “OK” to cover up his own misspelling of “all correct.”